I just replaced my condenser and recharged the A/C. Before this I had occasionally noticed a anti freeze like smell. Since recharging the system I am noticing it more often. It seems to get real bad when changing the a/c temp from 60 to 72 degrees. It smells like antifreeze and some fog/smoke blows out of the vents when doing this. Could this be the heater core starting to leak now? If so how much of a job is it. Thanks in advance